This invention relates to a protective casing for a shaving head. The shaving head to which this invention relates may contain one or more shaving blades and may be either an integral part of a one-piece, disposable safety razor system or may be a cartridge that is detachably engageable with the handle of a safety razor system.
The need for protective casings for shaving heads has long been recognized. Such protective casings protect both users from accidental injury from exposed cutting edges of shaving heads and protect the shaving blades themselves from nicks and other damage. In general, the prior art consists of two types of protective casings: a casing for holding an individual shaving head (disclosed, for example, in U.S. Pat. Nos. 4,587,730 and 5,095,621) and a tray-type casing for holding a plurality of shaving heads (disclosed, for example, in U.S. Pat. No. 5,518,114).
Each of these types of protective casings has certain advantages and disadvantages. For example, individual protective casings may be simple and inexpensive to manufacture; yet, they may be inconvenient both to a manufacturer and a user for storing together multiple shaving heads. In contrast, while a tray is convenient for storing together multiple shaving heads, its flexibility is limited because it can only store a fixed number of shaving heads. In addition, a tray may be more difficult and expensive to manufacture than individual protective casings because of the precision required for the uniform placement of the common walls between shaving cartridges.
Another type of protective casing has been disclosed in U.S. Pat. No. 4,601,392, issued to Althaus. Althaus discloses individual protective casings that may be frangibly connected in a side-by-side relationship to form a razor blade pack. While combining some of the advantages of individual and tray-type casings, the casings disclosed in Althaus still have several shortcomings. First, once a protective casing is broken off from the pack, it can no longer be reattached. Second, there is always the concern that a frangible connection, once broken, may be jagged and dangerous to a user. Third, if the pack is integrally molded, the number of shaving heads sold together in a pack is fixed.